The present invention relates to pole connector assemblies and devices, and more particularly to pole connector assemblies and devices for joining support post sections used in adjustable racks, shelving, and similar applications.
Many existing shelving and rack systems are constructed of one or more poles connected to one or more shelves or racks. In some cases, the shelves or racks can be adjustably connected to the poles at different heights. Also, each pole often includes two or more pole sections that are connected in an end-to-end fashion by pole connector devices or assemblies. Pole connector devices and the poles assembled with such devices are preferably strong, lightweight, easy to assemble (and in some cases, disassemble), and relatively inexpensive. However, existing pole connector devices fail to balance these design considerations well, invariably resulting in pole connector device designs that are lacking in one or more respects. Conventional pole connector devices and assemblies are often unreliable, heavy, slow to assemble and disassemble, expensive to manufacture, and difficult to properly align and adjust.
For example, many conventional pole connector devices include a plurality of pole inserts that are inserted into the ends of pole sections. These pole connector devices are used to connect adjacent pole sections in end-to-end fashion as mentioned above. Such pole connector devices can have one or more exterior threaded surfaces. Many types of pole inserts are die cast, and have threads machined into the exterior surface(s) of the inserts. The threaded pole inserts are threaded into threaded ends of the pole sections to connect the pole inserts to the pole sections and to connect adjacent pole sections together.
Some existing threaded inserts are formed of a single piece or assembly having a separate threaded portion on each end of the insert for threaded connection with an internally threaded pole section. Other threaded inserts are threaded only on one end for threaded connection with a pole section. In such cases, the threaded inserts are inserted into the ends of adjacent pole sections and are then connected together with a fastener to connect the adjacent pole sections. By way of example only, the fastener can be rod threaded on each end. After the inserts are inserted into the ends of adjacent pole sections, one end of this fastener type is threaded into a threaded aperture in one of the inserts. The opposite end of the fastener is then threaded into a threaded aperture in the other insert and is tightened to connect the adjacent pole sections together.
The machining required for threading conventional pole inserts is expensive and can represent a significant part of the cost of a shelving and rack system. Such machining also adds an additional step in the manufacturing process and can significantly add to the time needed to produce a shelving and rack system. Although a number of alternatives exist to machining threads into the pole inserts and pole section ends (e.g., casting or molding threads), each of these alternatives adds significant costs to the manufacturing process in one or more ways, such as through expensive molds and molding machinery, etc.
The use of threaded pole inserts can also add significant time to the pole assembly process, especially when several pole sections and several rack or shelf systems need to be assembled. Such inserts and pole sections can be difficult to thread together, and in some cases may not properly align to form a straight pole. If threaded correctly, an insert threads into a pole along a central pole axis extending parallel to the walls of the pole. In some cases, the threads on the insert may become misaligned with the threads of the pole during assembly, causing the insert to become misaligned with respect to the pole axis and result in an unstable pole connection. Such unstable pole connections can be difficult to detect by the assembler. In addition to misalignment problems, the process of tightening the pole inserts into the pole sections during assembly and of loosening such connections during disassembly can be difficult, often requiring significant strength and/or tools. Also, threaded inserts can loosen as a result of rack or shelf use and vibration, resulting in unreliable connections between pole sections.
Other types of pole section connectors do not employ threaded connections to the pole sections. For example, some pole section connectors employ inserts that are received into the ends of the pole sections and are attached thereto by adhesive or cohesive bonding material. Such pole section connectors can be difficult to properly align (while the bonding material sets and/or while the inserts are assembled with the pole sections). It can also be difficult for an assembler or user to detect when the bonding material has failed or is otherwise unsatisfactory for bearing normal loads. In addition, the use of bonding material for pole section connections can make pole disassembly problematic or even impossible.
In light of the problems and limitations described above, a need exists for pole assembly connectors that enable quick assembly and disassembly of rack or shelf poles, can be inexpensively manufactured, are easy to properly align and assemble, and provide a strong and reliable connection between pole sections. Each preferred embodiment of the present invention achieves one or more of these results.
In one aspect of the present invention, a pole connector assembly is employed between adjacent pole sections in order to construct a pole. Some preferred embodiments of the pole connector assembly have two inserts connected together by a fastener. Each of the two inserts is received within an open end of a respective pole section. The fastener is preferably received within an aperture in each of the inserts in order to connect the pole sections together.
In some preferred embodiments of the present invention, each insert has at least one projection that extends into the pole section in which the insert is received. Preferably, the projection can be deflected in order to engage (or more fully engage) the insert within its corresponding pole section. The projection can be deflected by the fastener or by one or more internal surfaces of the pole section as the insert is inserted within the pole section.
Preferably, the fastener is received within the aperture of the insert as mentioned above. By inserting the fastener in the aperture, the fastener preferably deflects the projection to engage the inside surface of the pole section and to thereby secure the insert in the pole section. In some preferred embodiments, the fastener and the aperture in the insert are threaded so that threading the fastener in the insert aperture causes the projection to deflect and to engage the inside surface of the pole section.
Any number of insert projections can be employed for purposes of securing an insert to a pole section. However, the insert most preferably has a plurality of such projections, each separated by a space so that each can be deflected with respect to the others. For example, the insert can have four projections that surround the aperture within which the fastener is received. The four projections can be separated by grooves in the insert (which grooves can be cuts made in the insert to define the four projections). When the fastener is inserted within the aperture, such as by being threaded into the aperture, the four projections expand and deflect from one another, and thereafter contact and preferably press against the inside surfaces of the pole section in which the insert is installed.
The projections of the inserts can engage with the pole sections in different manners in order to secure the inserts within the pole sections. In some cases, the projections press against the interior surfaces of the pole sections and thereby frictionally engage the inserts with the pole sections. In these and in other cases, the projections can have one or more features that mate or otherwise engage with one or more features on the inside of the pole section upon deflection of the insert projections. For example, the projections can have a circumferential groove therein which mates with a circumferential tongue on the inside of the pole section. The circumferential tongue can be defined by a circumferential recess on the exterior of the pole section. Such recesses are commonly used to connect racks and shelves to poles. When the grooved projections of the insert are deflected, the grooves on the insert mate with the internal tongue of the pole section to engage the insert with the pole section. Still other types of engagable elements and features on,the deflectable projections and on the pole sections are possible, each one of which falls within the spirit and scope of the present invention.
In some embodiments of the present invention, the inserts each have a cap portion that is preferably larger than the inner diameter of the pole sections being connected and that preferably abuts the end of a pole section. Although the inserts do not require a cap portion, this feature provides additional stability to the pole connection assembly. Also, the cap portion (e.g., a peripheral edge of the cap portion) can be chamfered, beveled, or otherwise recessed so that the pole connector assembly has a circumferential groove at the pole section interface to which shelves and racks can be connected.
The elements making up the pole connector assembly of the present invention are relatively simple and inexpensive to manufacture, particularly because a number of the embodiments employ only one threaded connection for each insert (as opposed to two threaded connections commonly used in existing pole connectors). In addition, the snap-fit and positive engagement provided by the inserts of the present invention help to provide a more reliable and stronger pole connection that is also easier to align and adjust. Also, assembly of the various embodiments requires minimal strength and skill, with no need to employ bonding agents or to align parts during the assembly process.
More information and a better understanding of the present invention can be achieved by reference to the following drawings and detailed description.